In a large bowl, beat the cream cheese and peanut butter together until smooth.
Add powdered sugar and mix until well combined.
Fold in the whipped topping gently until the mixture is smooth and fluffy.
Spoon the filling into the graham cracker crust and spread evenly.
Chill in the refrigerator for at least 4 hours, or overnight for best results.
Before serving, drizzle with chocolate syrup and sprinkle with chopped peanuts or mini peanut butter cups if desired.